气相色谱与紫外分光光度法评价石油烃类污染物的微生物降解过程

采用联合使用毛细管气相色谱法和紫外可见分光光度法,系统地研究了一种混合微生物体系对柴油的降解过程。研究结果表明,这两种简单方法的简单组合,弥补了单一方法的局限性,能够监测石油烃类污染物总体和主要组分的降解程度,实现对烷烃和芳香烃降解的分别评价。同时还表明,本实验采用的混合微生物体系对柴油具有很强的降解能力。     

无分流进样和交联、键合毛细管柱在石油饱和烃色谱分析中的应用

生油岩和石油中萃取分离出的饱和烃馏分,主要由碳数范围C_(11)～C_(50)正构烷烃、异构烷烃及环烷烃组成,饱和烃的气相色谱分析结果可以得出碳数分布、主峰碳、成熟度等一系列重要地球化学指标数据,是目前国内外应用最多最广的石油地球化学分析项目之一。     

绿脓素对降解原油的微生物菌群的影响

铜绿假单胞菌WJ-1是从蒙古林油田油水样中分离得到的一株能够以原油为唯一碳源, 通过合成某些代谢产物增加其环境竞争力和存活率的烃降解菌. 用氯仿从WJ-1LB培养液中萃取绿脓素, 气相色谱-质谱法(Gas chromatograph-Mass Spectrometry, GC-MS)分析得该物质为1-羟基吩嗪. 通过在原油培养基中加入和未加入0.2 g/L绿脓素, 培养32 d来研究绿脓素对烃降解菌群T2的群落结构和原油降解能力的影响. 变性梯度凝胶电泳(Denaturing Gradient Gel Electrophoresis, DGGE)分析结果表明: 在32 d的原油降解中, 含有绿脓素的培养液中T2菌群多样性减少. 气相色谱和棒薄层层析分析得: 含有绿脓素的培养液中原油的芳香族烃等非烃类和正构烷烃中长链组分的降解率比未加入绿脓素的要低. 超氧化物歧化酶(SOD)和过氧化氢酶(catalase)活性检测结果表明: 不同菌体的过氧化氢酶和超氧化物歧化酶含量与活性不同, 引起对绿脓素抗性的差异. 可见绿脓素对烃降解菌群的结构和原油降解能力有负面影响.     

污染土壤中主要石油降解基因AlkB和Nah定量检测方法的建立和应用

建立了SYBR Green I实时荧光定量聚合酶链式反应(Real Time-qPCR)检测油田污染土壤中烷烃降解基因AlkB和萘降解基因Nah的方法。比对相关降解石油菌株的GenBank序列,设计合成针对烷烃和萘降解基因扩增引物AlkBf/AlkBr和Nahf/Nahr。将纯化的常规PCR胶回收产物与pEASY-T1载体连接,转化到感受态细胞培养。提取并梯度稀释阳性克隆质粒,构建Real Time-qPCR标准测定曲线。25μL扩增体系最佳反应条件:前后引物终浓度为0.2μmol/L,12.5μL 2×TransStart Top Green qPCR SuperMix,AlkB和Nah基因最适退火温度分别为50℃和57℃。Real Time-qPCR技术显示出很高的灵敏性和重复性,比传统PCR技术灵敏度高100倍。对采集于某油田3个功能区的14土壤样品中AlkB定量检测显示,石油污染严重的采油区含有最高的AlkB拷贝数,污染较轻的生活区AlkB拷贝数最少;Nah基因分布均匀。     

快速气相色谱法分析石油饱和烃

提出了一种快速分析原油和岩石抽提物中饱和烃组分的毛细管气相色谱(GC)方法。由于在该方法中采用了细内径毛细管柱,故饱和烃的GC分析周期由原来的80~90 min缩短至15 min,分析速度加快约5倍,大大提高了工作效率和仪器通量,使石油饱和烃得到了很好的分离分析。该方法符合中华人民共和国石油天然气行业标准SY/T5120-1997的要求。20万理论塔板数的细径柱的应用,可供石油中异构烷烃,尤其是甾烷、萜烷类的气相色谱/质谱(GC/MS)快速分析方法及芳烃的GC快速分析方法借鉴。     

300号液体石蜡中正构烷烃含量的测定

正构烷烃含量的测定,一般采用气相色谱法。荆门炼油厂用OV—101毛细管柱气相色谱法测定300号液体石蜡中的正构烷烃的含量。此法因使用毛细管柱,每次分析要2小时左右,故不适应大量样品分析的需要。为此我们用美国HP公司5840 A型气相色谱仪的高     

石油中间馏分中异构烷烃的分子识别

以石油加氢异构中间馏分及直馏柴油为研究对象,采用气相色谱/质谱联用技术对异构烷烃的分子形态进行了研究。实验表明各碳数异构烷烃组分在毛细管气相色谱柱上表现出明显的按取代基个数簇分离的现象。对异构烷烃的异构程度进行了表征,得到不同取代基个数的异构烷烃的保留指数(RI)定性表;同时根据化合物的质谱断裂规律,参考文献数据并结合碳数及沸点规律,对73种甲基取代的异构烷烃及10种生物标记的化合物单体进行了结构定性,并计算了保留指数。为在分子水平上认识航空煤油及柴油等石油中间馏分中的异构烷烃提供了基础。定性结果表明:在研究的加氢异构中间馏分中,异构烷烃主要由单取代基和二取代基的异构烷烃组成;而在直馏柴油中,单取代基异构烷烃和类异戊二烯类生物标记化合物丰度较高。     

色谱与色谱/质谱法相结合分析热裂解汽油C9馏分

采用毛细管气相色谱-氢火焰离子化检测器（CGC-FID）和气相色谱-质谱法(GC/MS)分析了热裂解汽油C9 馏分的组成。实验使用PONA毛细管气相色谱柱(100 m×0.25 mm i.d.×0.5 μm),根据烃类化合物在PONA柱上的保留规律,以正构烷烃标样保留值作为碳数分布依据,定量分析了裂解汽油C9 馏分中烃类化合物的碳数分布和单体烃含量;用GC/MS联用技术和CGC保留值定性法相结合对裂解汽油C9 馏分中相对含量大于0.2%的39种化合物进行了定性。     

柴油中正构烷烃的高温气相色谱分析

利用高温气相色谱法对柴油中正构烷烃的碳数分布及含量进行了分析。同时根据所得数据计算出正构烷烃的平均相对分子质量及平均碳原子数。试验表明,气相色谱的最佳测定条件为：柱初温60℃,柱终温330℃,升温速率6℃／min,汽化室温度350℃。分析出吐哈两种柴油中C11～C19的正构烷烃均占分析总量的75％以上,吐哈0^#与-10^#柴油正构烷烃的平均相对分子质量、平均碳原子数分别为214．57、15．18和203．34、14．38。所得数据为设计研究针对吐哈原油有效降凝剂提供了参考数据。     

气相色谱法鉴别缓慢生长分枝杆菌

采用毛细管气相色谱法对９种缓慢生长分枝杆菌的化学成分进行了分析。结果表明,不同菌种的色谱图存在明显的差异。对７５株临床菌株进行色谱法鉴别,并与传统生物学鉴定法作了对比。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.